Japanese knotweed on your boundary: stopping the spread and staying on good terms with neighbours

Japanese knotweed · 4 min read

Finding Japanese knotweed near your boundary can feel worrying, whether it is in your garden, at a property you let or on a business site. In most cases it is manageable, but it needs to be dealt with properly and documented. Acting early, before it spreads onto a neighbour's land, keeps the job smaller and the conversation friendlier. This guide gives a general overview. It is not legal advice.

Who this guide is for

• Homeowners, including anyone who has recently bought and found knotweed in the garden
• Landlords who want to deal with it before it becomes an issue with tenants or neighbours
• Businesses and long-term sites, such as caravan sites, where knotweed is creeping towards a boundary

Buying or selling a home? See Japanese knotweed and selling a house.

Why act before it crosses the boundary

Knotweed spreads underground through its rhizomes, and even small fragments can regrow. A stand near a fence rarely stays on one side for long. Early action avoids further spread, damage, stress and cost, and it is much easier to talk to a neighbour about a small patch than a large one.

Talking to your neighbour

Most boundary problems are easier to sort out with a calm, early conversation. Many people do not realise knotweed is on their land, or that it is spreading.

• Take dated photos of what you can see on both sides
• Let your neighbour know what you have found and share the survey photos
• Agree access if work is needed on their side. With their permission, we can check and treat their side as well as yours
• Keep a simple note of what was agreed and when

How it is dealt with

At the free in-person survey we identify the plant, assess the extent and recommend the right approach: herbicide treatment, stem injection, excavation, a root barrier along the boundary, or a combination. You get a written report with photos and a fixed price quotation, including VAT. See treatment vs excavation for how each works, and our Japanese knotweed page.

Your paperwork, and it is yours to share

• A survey report identifying the plant and recording its extent, with photos
• A management plan setting out the work and recording each visit
• A guarantee certificate when the work is complete
• Evidence of monitoring visits

Your paperwork is yours to share: with neighbours, tenants, managing agents, buyers or surveyors. Some firms ask you not to share theirs; we don't. If you need a formal report, a survey report from a Certificated Surveyor in Japanese Knotweed (CSJK) confirms whether it is knotweed and maps its extent and the risk to the boundary. Formal reports are £240 (£200 + VAT). The in-person survey and quotation are free.

Guarantee offered on every job

A minimum 5-year guarantee comes as standard, available for up to 20 years, unless your quotation says otherwise. After the first 5 years it can be extended at £60 a year including VAT (£50 + VAT). It covers regrowth from the plants we removed or treated, including spread into a neighbour's garden where they give us access, with as many checks and treatments as we judge are needed, at no extra cost.

If you are a landlord

• Get a survey so you know the extent and the risk to the boundary
• Let tenants know what is being done and when, and ask them not to cut, strim or dig it
• Share the management plan with your managing agent and, if it is near the boundary, your neighbour

If you run a business or long-term site

• Survey the whole site, not just the patch you can see. Knotweed often follows boundaries, banks and verges
• Plan the work around how the site is used, so it fits your busy and quiet periods
• Keep the management plan with your site records so staff know what not to disturb

Do not make it worse

• Do not try to dig it out or cut it back quickly yourself. That can spread it and cause bigger problems
• Do not put it in garden waste or compost. Knotweed waste must be disposed of correctly

Frequently asked questions

Knotweed is coming from my neighbour's garden. What can I do?

Take dated photos, talk to your neighbour early and send us a photo for a free ID. With your neighbour's permission, we can survey and treat on both sides of the boundary.

Can you treat both sides of the boundary?

Yes, where your neighbour gives us access. Our guarantee also covers spread into a neighbour's garden where they give us access.

Can I share your report with my neighbour or managing agent?

Yes. Your paperwork is yours to share. Some firms ask you not to share theirs; we don't.

What guarantee do you provide?

A guarantee is offered on every job: a minimum of 5 years as standard, available for up to 20 years.

How much does it cost?

The in-person survey and quotation are free, and every quotation is a fixed price including VAT. Formal survey reports from a Certificated Surveyor in Japanese Knotweed (CSJK) are £240 (£200 + VAT).

I recently bought my home and found knotweed. Can you help?

Yes. We survey, treat and give you a management plan and guarantee certificate for your records. If it is near the boundary, acting now helps stop it spreading next door.

Japanese knotweed near you

Surrey · Sussex · Kent · Hampshire · Berkshire · Buckinghamshire

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• Japanese knotweed and selling a house: management plans, guarantees and mortgages